The invention has been developed with a view to possible applications in new generation mouses (or mice) that, instead of detecting motion imparted by the user via a ball or sphere as used in current mice, are capable of using a video sensor or other types of sensors that provides an output signal with an array of digital values encoded in N bits, such as capacitive sensors used in touch-chips for detecting fingerprints, in new-generation telephones or the so-called portable digital assistants (PDA), or even in optical pens for text processing and similar applications.
In this context, it is necessary to process the video frames generated in output by the video sensor (telecamera) and determine the motion imparted by the user to the object (mouse, pen, etc.) on which the sensor is mounted.
In these situations, the sensor captures the images in movement of the surface that is being passed over. This motion can be reconstructed from the relative positions of the successive images that are sampled by the sensor. In the case of an optical mouse, once the relative motion between two images is identified, it is possible to deduce the displacement that must be given to the mouse pointer on the screen. The same information can obviously be used in different ways for other applications, such as those previously mentioned.
For applications of the above-described type (optical mice for example), recourse to complex, phase-correlation algorithms between the images and/or edge detection is well known. In all cases, the solutions are characterized by high computational intensity.